Vacuum cleaner



June 9, 1953 G. E. LOFGREN E'TAL 2,641,330

VACUUM CLEANER Filed Jan. 25, 1950 ll Sheets-Sheet 1 mmvroxs.

GusmF EINAR LOFGREN ROBERT c. LAMPE JOHN r FERRARIS BY W 7 TTORNEX June9, 1953 G. E. LOFGREN ET AL 1,3

' VACUUM CLEANER Filed Jan. 25, 1950 ll Sheets-Sheet 2 GUSTAF EINLOFGREN ROBERT- C. L MPE JOHN T FERRARIS JNVHVTORS; A 12 June 9, 1953 G.E. LOFGREN EI'AL VACUUM CLEANER l1 SheetsSheet 5 Filed Jan. 25, 1950INVENTORS. gUSYFlF EIAMR LOFGREN OBERT c. LAMPE JOHN T FERRARIS 'M 2TTORNEY INVENTORSJ GUSTAF EINAR LOFGREN ROBERT c. LAMPE 11' Sheets-Sheet5 JOHN T maze/1121s B gnaw?! G. E. LOFGREN ETAL VACUUM CLEANER June 9,1953 Filed Jan. 25, 1950 June 9, 1953 G. E. LOFGREN ET AL 3 VACUUMCLEANER Filed Jan. 25, 1950 11 Sheets-Sheet 7 INVENTORS. GUSTAF EINARLOFGREN 10 11% ROBERT c. LAMPE JOHN T FERRARIS June 9, 1 953 G. E.LOFGRENY ETAL 2,641,330

VACUUM CLEANER Filed Jan. 25, 1950 ll Sheets-Sheet 8 INVENTORS. GUST/IFEINAR LOFGREN ROBERT C. LAMPE JOHN T. FER/M1215 By 71.4.4; M

T TORNEY.

VACUUM CLEANER ll Sheets-Sheet 9 Filed Jan. 25, 1950 mm Tm M F R IRMMAHMTI N WWW Wm H w M 4 NH Q 2 -m 4/ /N/ m Q g r t H l June 9, 1953 G. E.LOFGREN ETAL 2,641,330

' I VACUUM CLEANER Filed Jan. 25. 1950 I1 Sheets-Sheet l0 :aoo

. INVENTORS. GUSTAF EINAR LOFGREN ROBERT c. LAMPE JOHN T FERRARIS BY TORNEV.

June 9, 1953 G. E. 'LOFGREN ETAL VACUUM CLEANER ll Sheets-Sheet 11 FiledJan. 25, 1950 INVENTORS. GUSTAF EINAR LOFGREN ROBERT c. LAMPE JOHN 77FERRARJS BY 2 M TTORNEI/ Patented June 9, 1953 UNITED STATES PATENTOFFICE 2,641,330 VACUUM CLEANER Gustaf Einar Lofgren, Riversid Robert C.Lamps, Stamford, and John T. Ferraris, Cos

Cob, 001111., assignors to Electron (Loriaoration, 016 Greenwich, Conn,a corporation of Delaware Application January 25, 195.0, Serial ND.140,394

22 Claims. 1

This invention relates to improvements in a vacuum or suction typecleaner having automatic controls. More particularly, it embraces anautomatically conditioned tank type cleaner having self-containedcontrol mechanisms for removing accumulated dirt in packaged formreadied for immediate disposal. With this cleaner the dirt entrained inthe'inccming air suction stream is collected in a porous disposable baglocated within the cleaner and when the collected dirt effects apredetermined change in the operating efficiency of the cleaner, thelatter automatically shuts itself off and disposes of the dirt-filledbag by ejecting the latter from the cleaner.

It is a major object of this invention to provide a new and improvedvacuum cleaner having automatic means for disposing of dust and dirt byejecting from the cleaner a self-sealing porous and disposable paper bagfilled with dust and dirt separated from the suction air stream drawnthrough the cleaner.

It is a further and important object hereof to provide completelyautomatic means for efiecting the operation of a dust bag ejectingdevice upon the attainment of a predetermined condition or status ofoperation within the cleaner.

A still further object is to provide a vacuum cleaner which has a largedust collecting capacity and which operates at a substantially uniformefficiency.

A further object of this invention is to provide a device which avoidsthe inconveniences present in the conventional suction type of vacuumcleaning device using the customary cloth or paper dust bag whichperiodically necessitates indiscriminate removal or replacement in orderto maintain a semblance of efficient operation, such bag removal stepsbeing heretofore effected manually and with considerable difficulty anddiscomfiture on the part of the operator.

Still other and further objects willbe disclosed hereinbelow or willbecome evident to those skilled in the art after a carefiil study of thefollowing description together with the appended drawings wherein: v

Figure 1 is a perspective View of the complete cleaner as seen from theair intake end, sans nozzle, conventional wand and hose;

Figure 2 is a perspective view of a portion of the cleaner and hosetaken from a position simiejector plate pushed back and a conventional 2cloth type bag in exploded view and with its cloth portion partly cutaway, the bag being in position for insertion into the dust bagcompartmerit of the cleaner housing;

Figured is a vertical sectional view taken on the line 1 -4 of Figs. 1and '7';

Figure 5 is a horizontal sectional view taken on the line ii-=5 of Figs.1 and '7;

Figure 6 is a partial horizontal sectional view taken on the line 6-=$of Fig. 2, showing the cover opened and the scissors ejector mechanismfully distended;

Figure '7 is a front plan View of the cover of Fig. 1 in closedposition;

1 Figure 8 is a vertical sectional view taken on the line 8-8 of Fig.12, showing the cut-out switch, which cooperates with a projection onthe non-disposable cloth dust bag of Fig. 3 for disconnecting theautomatic controls from operation;

Figure 9 is a vertical sectional view taken on the line 9-8 of Fig. 7showing the parallel linkage of the hose coupling assembly to the cover;

Figure '10 is'a sectional view taken on the line iii-it of Fig. '7,showing the manually operable button for releasing the front cover;

Figure '1-1 is a sectional view taken on the line [I -N of Fig. 7showing the manually operable switch actuating button for energizing anddeenergizing' the motor fan unit;

Figure 12 is a horizontal sectional view taken on the line 12-42 of Fig.'7 showing the linkage control for automatically releasing the dust bagejector device;

Figure l3 is a wiring diagram including some of the pneumatic controls;and

Figure 14 is an exploded perspective View with portions cut away insection showing the eleo-' tro-pheuinatic control unit and details ofits internal construction.

It is a feature of this invention that the functioning of the cleaner initsdu'st disposal capacity sequenceof operations terminating in theejection'oi the dust-filled bag is effected in a series the cleanerbetween the inside and the outside or the dust-collecting bag'. Thisresults in a-contmuous and progressively increasing force being exertedupon a pressure differential measuring diaphragm, the opposite sides ofwhich are subjected tothe di'iie'r'eht pressures built up on the 3outside and inside of the dust bag, the chamber on one side of thediaphragm being connected to an opening communicating with the cleanside of the dust bag, the space on the other side of the diaphragm beingconnected to an opening communicating with the dirty side of the dustbag. Then, upon the attainment of a predeterin the ejection of thedust-filled'bag from'the cleaner housing.

In a preferred embodiment, the differential pressure diaphragm actuatesa switch which closes a circuit for energizing an electromagneticallyactuated armature or solenoidal unit. The armature or plunger of theelectromagnetic device in turn opens a valve for admitting suction fromthe motor fan unit to actuate a second diaphragm which operates througha series of linkages to release (1) a first ejector mechanismrestraining latch and thereafter or in timed relation thereto (2) thecover of the cleaner housing. Then, the cover after a predeterminedangular travel toward its fully opened position in turn breaks a circuitcutting off the power supply to the motor fan unit. Continued travel ofthe cover towards fully opened position subsequently releases a secondand final ejector restraining latch for actually releasing the bagejector mechanism for dust bag ejection, whereupon the dustfilled bag isexpelled from the cleaner housing and deposited upon the floor. Duringthese cover opening steps, the timely breaking of the motor fan circuitresults in a progressively slowing down in motor fan speed andconsequently the air suction stream also progressively decreases toavalue at which highly effective bag ejection is more readily attained.

Thus in accordance with this preferred embodiment of the invention,automatic dust bag ejection is effected by mechanical means, after beinginitiated by a tripping mechanism including a pressure differentialmeasuring device which actuates a responsive triggering apparatus. Thepressure differential measuring device is conditioned for operation byutilizing the air pressure difference built up within the cleaner casingby dust layers collected in the dust bag. This pressure difference isestablished between the inside and outside of the dust collecting bagand is communicated therefrom by appropriate conduit means throughoutthe dust collecting process.

Referring now more particularly to the drawings, vacuum cleaner housing[8, Fig. 1, is a hollow casing having a handle .I I. It is appropriatelysupported on a pair of runners l2. The suction or inlet portion of thecasing It is provided with an air inlet nozzle and wand (not shown)together with a suitable flexible hose l3, Figs. 2, 3, and connectingcoupling 14a fitted into a movable hose coupling assembly [5 mounted oncover l6. Cover I6, Fig. 6, hinged at I! to front body ring and biasedto open position by spring l8, effects with casing If! an air tight sealformed by rubber ealing ring member l9, cardboard disc 3| of dust bagand sealing ring 22 positioned in the bag insertion opening of frontbody ring 2!], Fig. 5. Tubular member 21 of the hose coupling assemblyl5 extends through the opening 32 cut in cardboard disc 3| well into thedust collecting receptacle 30, and is sealed against disc 3| by rubbersealing ring 19. Switch button Hia on cover l6 provides the on-and-offmanual control for the cleaner unit.

A perforated sleeve 23 is aflixed at one end to front body ring 20 andis adapted for supporting dust bag 30 (of disposable paper or clothconstruction). This entire unit (sleeve 23, body ring 28, etc.) isslidably fitted within the open end of cleaner housing It and is aifixedthereto by retaining screws. 24, Figs. 1, 2, 3, etc. In the embodimentshown, sleeve 23, reinforced by lateral stiffening plate 25 and baserods 26, is substantially rectangular in cross-section and is thusadapted to take a bag 36 of substantially similar but slightly smallercross-section, Figs. 2, 3 and 4.

Two types of dust bag are illustrated, a disposable and a permanent one.Dust bag 30, Fig. 2, comprises a dust receptacle of paper or similarlyair-pervious, dust-impervious, material 33 afiixed at its mouth to therear surface of a hard paper or cardboard disc 3!, the latter beingclamped between rubber sealing ring l9 of hose coupling assembly l5 andthe open end of front body ring 29 with the aid of sealing ring'22.Cardboard disc 3! has a central opening 32 through which tubular member2| is inserted in order to introduce the air and entrained dust directlyinto the interior of dust bag 30. The permanent cloth bag of Fig. 3 isused when the automatic controls and dust bag ejection are not desired(see detailed description below).

The entire inner surface of perforated sleeve member or dust bagreceiving compartment 23 is provided with apertures 21, Figs. 3, 4, and6, in order to permit suction air current to pass freely therethroughand into chamber 40, the air also passing to compartment 59 containingthe ejector scissors 53 and its associated expulsion spring assembly 5!.Thereafter the suction air current passes through motor fan compartmentlfi which contains mounted therein fan (I and motor 72. The fan isprovided with an air inlet l3 through which the air passes to thehousing of motor 72 and out through louver open- The scissors ejectormechanism 5!, 53, Figs. 4, 5 and 6, for operating the bag ejector plate52 is in the form of a collapsible spring loaded lazy tongs 53 which canbe collapsed into fully flexed (loaded) condition, Fig. 5, by pushingback ejector plate 52 hingedly attached by pins to the front pair ofscissors blades 52a. Mutually intermeshing gear teeth 54 cut in coactingportions of the front pair of scissors blades keep plate 52 orientedcorrectly throughout the extent of its travel. U-shaped frame member 55afiixed to the rear end of perforated sleeve 23 supports the ends of therear pair of scissors blades 53c by holding the latter between a pair ofsleeves 56, all being bearinged on pin 5?. The scissors mechanism isbiased to fully distended position 3 Beans-bell crank-6'3 Fig. 12,-forms: another compositabell' crank" biased to: latching positionbispring-59.

The above'latchesfor restraining the ejector mechanismv are operatedthrough appropriate linkages; Thus rearlatch 63 is moved toreleasin-gposition by automatictriggering initiated by pneumatically actuatedmeans: (described below) and transmitted through link- 8 I, and a bellcrank formedof lever arm 83, pin 85 and lever arm .37, Fig. 12, whilelever arm 83 is actuated in turn by bell crank 89, Figs. 4, 9 and 12,fulcrumed at 9i: and linked directly to thepneumatically operatedtriggering device 250.

Front latch 62- is'moved' to releasing position by-thefinal openingstages of. the released front cover- IB through link 82 and abellcrankform oflever arm 84, pin 86', and lever arm 88, while thelatter is actuated byslide or draw bar 92 which is pulled outwardlyby acam" 94 on the parallel linkage I I501" the hose coupling assembly I5With' this particular latching device for restraining the scissorsejector' mechanism 5|, plate 521s held in loaded-position until cover I6is practically fully opened. Cover: I6 is normally held closed by latch"I00, Figs. 2, 3 and 10, fulcrumedat IUI and biased to retain cover $5 inclosed position by tension spring I02.

Thecovermay be opened for inspection of the bag-and its contents,however, without neces sarily ejecting the dust bag, by pressing releasebutton IE?) on cover IB- downwards and (Fig. 10) causing plunger I05held'throughelongated slot I06 by retaining screw I01 and biased upwardsby spring I08 to contact latch I00. Pressing button IBb forces plungerI05 downwards against latch Ill'fl thusreleasing cover I6. Then, evenwith front latch 62 released by the-opening of cover IE to. itsfullextent, rear latch 63 restrains scissors ejector 53 from dischargingthe dust bag. Latch 63-thus serves as an auxiliary safety latchpreventing the dust bag in either full'or empty condition from beingejected upon manually opening cover IE. on the other hand, with cover I3closed, latch '52 similarly serves as an auxiliary safety latchpreventing the compression and jamming of bag 30 within sleeve member 23even though latch 63 may have been released by the triggering action of.pneumatically operated device 250.

It is to be noted that pneumatically operated device 250 in additiontotriggering rear ejector latch 63 also releases cover restraininglatchI00 by" actuating lever I3I, Figs. 10', 12, 13, ful-- crumed at I32.

The parallel linkage of the hose coupling assembly I5 to the cover I6 ismost clearly-shown in Fig. 9, where bell crank H5 fulcrumed at IIB tofrontring 20 and at IIT to hose coupling assembly I5'forms one link ofthe complete parallel linkage while cover II; (itself), fulcrumed at I'Ito. front ring 20 and at H8 to hose couplingassembly I5, forms the.other link.

Button. 16a on cover 'I 5' operates the switch button. III), Fig; 11, ofa conventional on-and-ofi toggle type snap switch 3H1 through plungerIII slidably held in a groove H2 by retaining screw H3 and biasedupwards by spring IM. Plunger III actuates bell crank I23 fulcrumed atI2I through one arm thereof, the other I22 of which operates switchbutton III]. However, although button IBa may be'usedwto start and stopthe motonfan unit while the' cover I6 is closed, the opening Fig. 9 ofcover" I3" causes 2; lug 95 of parallel: linkages I I5? to" release. oneleg: of: a: U

shaped" switch rocker arm. 96', Figs.=11, 12 andz13'; fulcrumed'at'flland biased for clockwise rotation by spring 98'. Thusiwhen the coverisuopened: theother leg of switch arm actuates'pin 99 of.

the-on-and-ofl switch 3! to its off position, thereby stopping'the motorfan unit andother wise deenergizing: the entire cleaner unit.

The electricaland pneumatic control units are closely and operativelyinterrelated. The pneumatic system includes a pressure difierentialmeasuring control device 200, Fig. 14, comprising an -upper-casing-2Illand a lower casing 202 separated by a diaphragm 203 pneumaticallysealed. therebetween. The space in the upper casing abovewdiaphragm 203is connected by communieating conduit 2| I), Figs. 4 and 14 to opening'21 5; Fig. 5, on the dirty or dust collecting side of the dust bag. Thespace in the lower casing below diaphragm-203 is connectedbycommunicating conduit 22D, T-shaped coupling 22I and common conduit225to 'opening' 233, Figs. 4, 5, 6 and 12, on the clean side of the dustbag. The remaining connection from T-shaped coupling 22! communicates bymeans of conduit 23I with one side of valve 243' comprising valve stem 2H and valve face-242' biased'to closed position by spring 243.. Whenvalve 24:; is open it communicates high suction to the interlor'ofpneumatically" operating triggering device 250; comprising a lowervcasing 25I pneumatically sealed by diaphragm 252 biased to distended orupward position by spring 253 and capable of actuating trippingmechanism through link member 254.

The electrical system for energizing the motor. fan unit andtheelectrical controls'are clearly shown in diagrammatic form in Fig. 13.Vacuum cleaner electrical cord 303 conveys current from the house linesat volts to terminal strips 301 located within the cleaner housing andfrom which one line 302 goes to motor 12, while the other line goes tomotor I2 through a circuit including line 355, on-and-of'f switch 315,line 3H and line 3 I 3. The circuit for energizing the elec--tricalcontrols comprises line 320, cut-out switch 32 I, line 322,electromagnet 325, line 325, pneue matically operated switch 321 ofpressure difierentialpneumatic control unit 200, and line 328 to thehouse circuit'through the cleaner cord. 330. Cut-out switch 32I, Figs. 8and 13, is normally closed; bell crank IB'I' fulcrumed at leebeingbiased to switch closing position by spring I99 except when a specialcloth bag unit Fig. 3 (described'below) is used for dust collection. Theswitch 321 of pressure'differential pneumatic control'unit 200'comprisesa biasing spring 339, 14, which serves as a conducting element and formaintaining switch 321 normally open, together with contacts 33I and332.

In detail and particularly with respect to the operation of thepneumatic and electrical controls, and referring especially to Figs. 13and 14 where details of structure are clearly illustrated, the forceexerted on the pressure differential diaphragm 2133- progressivelyincreases with continued dust collection, until it attains sufficientvalue to actuate switching means 32'! and complete a circuit by closingcontacts 3 3i and 332m pressure differential controlunit 21W Figs. 4,13; li and thereby energize electromagnet 325. The armature 350 ofenergized electromagnet 325 ful-. crummed at 35! and biased by spring352 to holdv valve 253 more securely closed, thenmovesdownwardly and'opens valve 240 allowing high;suc:.-

ti'cnto be-bonnnunicated: to: and: operates.

phragm 252' which in turn through 'a series of linkages 254, 255, bellcrank 89, etc., releases rear latch 53, Figs. 4, 6, 9 and 12, holdingejection plate 52. Also by actuating lever l3l, Figs. 12 and 13,diaphragm 252 by way of linkage 254 trips cover releasing latch I00,Figs. 4, 10 and 12, which latch holds cover l6 closed against springtension. The release of cover [6 first breaks a circuit at the contactpoints of switch 3N through release of rocker arm 96 which is biased byspring 98 to throw switch 3 l U to 01f position, Figs. 9, 11, therebydeenergizing the motor fan unit. Thereafter the front cover continues toopen and after opening substantially 90, mechanical trigger mechanismcomprising cam 94 of parallel linkage l l 5 trips draw bar 92 releasingfront latch 62 and hence the bag ejector mechanism 5| through apreviously traced series of linkages, allowing the bag ejector plate 52,Figs. 4, 6 to push the bag forward and throw the bag and its containeddirt out of the cleaner casing.

The ejector plate 52 moves forward and outward when released until stops50, Fig. 6, abut in the forepart of the scissors mechanism 53. Themomentum of the moving dust-filled bag causes it to continue onward inits own trajectory out of the cleaner casing after which it comes torest on the floor.

The cloth bag shown in Fig. 3 is used when it is not desired to effectdust bag ejection. With this bag, a projection I15 on the lower edge ofthe metal ring 176 to which clot-h dust bag I1! is attached pushesagainst the upper end of bell crank I91, Fig. 8, interrupting theelectrical circuit of the control mechanism Fig. 13. then decideshimself when to empty this cloth bag. To empty this cloth bag, innercover H8 is removed by releasing two latches I19, whereupon the dust anddirt is shaken out manually.

Various other details of construction are shown in the accompanyingdrawings. Thus, the base plate ltil, Fig. 4, sealing oft the housing atthe bottom of the dust bag and screen compartment 48 together withdepending partitions l8! and E82 forms a bag storage chamber I85 (seealso Fig. l), which may also be used for storage of a cord reel. Leafsprings I90 keep the inner folded end of paper dust bag 30 from jammingunder plate 52 and between the bottom edge of plate 52 and the floor ofthe dust bag compartment 23. The angularly bent portion 52a of plate 52serves to keep the bag from crimping and jamming during ejection.

It is to be understood that the invention is not to be limited to thevarious structural features illustrated and described but that the samemay be variously otherwise embodied within the scope of the appendedclaims.

What we claim is:

1. In a vacuum cleaner, the combination comprising a casing formed withan opening, a dust bag removable from said casing through said opening,a cover member for said opening, an inlet conduit having its inner endcommunicating with the interior of said bag, means for inducing flow ofair through said conduit into said bag, and a control member movable toopen said cover in response to variations in the difierential of the airpressure existing in said conduit at a point spaced outwardly from itsinner end and the air pressure existing in said casing between said bagand said flow producing means.

2. In a vacuum cleaner, the combination comprising a casing formed withan opening, a dust bag removable .from said casing through said Theoperator opening, a cover member for said opening, an inlet conduithaving its inner end communicat- -ing with the interior of said bag,means for inducing flow of air through said conduit into said bag, adiaphragm subject on one side to the air pressure existing in saidconduit at a point spaced outwardly from its inner end and on the otherside to the air pressure existing in said casing between said bag andsaid flow producing means, and means responsive to movement of saiddiaphragm for opening said cover.

3. In a vacuum cleaner, the combination comprising a casing havingcompartments and an opening, a movable cover for said opening,releasable means for holding said cover in closed position, means forproducing a flow of air through said casing, a dust bag in said casingin the path of said air flow for separating entrained dirt from saidair, means responsive to a predetermined change in the pressurecharacteristics between predetermined compartments within said casingfor operating said cover releasing means, manually operative means foroperating said cover releasing means, and means for ejecting said dustbag actuated only by opening of said cover in response to said change inpressure.

4. In a vacuum cleaner, the combination comprising a casing having anopening, a movable cover for said opening, releasable means for holdingsaid cover in closed position, means for producing a flow of air throughsaid casing, a dust bag in said casing in the path of said air flow forseparating entrained dirt from said air, means responsive to theestablishment of a predetermined pressure difference between the insideand outside of said dust bag for operating said cover releasing means,releasable means for ejecting said dust bag, means responsivesubstantially simultaneously with the opening of said cover for placingsaid releasable bag ejecting means in condition for operation,additional means responsive to the opening of said cover fordeenergizing the air flow producing means, and further means responsiveto the complete opening of said cover for ei fecting the operation ofsaid releasable bag ejecting means whereby the bag ejecting means iscapable of more effective ejection of the dust bag.

5. In a vacuum cleaner, the combination comprising a casing having anopening, a movable cover for said opening, releasable means for holdingsaid cover in closed position, means for producing a flow of air throughsaid casing, a dust bag in said casing in the path of said air fiow forseparating entrained dirt from said air, air pressure means foroperating said cover releasing means, valve means for controlling saidair pressure means, electromagnetic means for actuating said valvemeans, differential air pressure responsive means operative upon theattainment of a predetermined pressure difierence between the inside andoutside of the dust bag for energizing said electromagnetic means, andadditional means responsive to the opening of said cover for ejectingsaid dust bag.

6. In a vacuum cleaner, the combination comprising a casing having anopening, a movable cover for said opening, releasable means for holdingsaid cover in closed position, means for producing a flow of air throughsaid casing, a dust bag in said casing in the path of said air flow forseparating entrained dirt from said air, means responsive to apredetermined change in the pressure characteristics within and withoutsaid dust bag for moving said dust bag to a predetermined and additionalmeans responsive to the opening of said cover for ejecting said dustbag.

7. In avacuum cleaner, the combination comprising a casing having anopening, a movable cover for said opening, releasable means forholdingsaid cover in closed position, means for producing a flow of air throughsaid casing, a dust bag in said casing in the path of said air flow forseparating entrained dirt from said air, air pressure means foroperating said cover releasing means, valve means for controlling saidair pressure means, electromagnetic means for actuating said valvemeans, differential :air pressure responsive means operative upon theattainment of apredetermined pressure difference between the inside andoutside of the dust bag for energizing said electromagneticmeans,releasable means for ejecting said dust bag, means responsivesubstantially simultaneously with the opening of said cover for placingsaid releasable bag ejecting means in condition .for operation,additional means responsive to the opening of said cover fordeenergizing the air flow producing means, and further means responsiveto the complete opening of said cover for effecting the operation ofsaid releasable bag ejecting means.

8. In a vacuum cleaner, the combination comprising a casing having anopening, a movable cover for said opening, releasable means for holdingsaid cover in closed position, means for producing a flow of air throughsaid casing, a dust bag in said casing in the path of said air flow forseparating entrained dirt from said air, releasable means for ejectingsaid dust bag, pneumatically operable diaphragm means for operating saidcover releasing means and for placing said ejecting means in conditionfor operation, valve means for controlling said pneumatically operablemeans, electromagnetic means for actuating said valve means,differential air pressure responsive means operative upon the attainmentof a predetermined pressure difierence between the inside and outside ofthe dust bag for energizing said electromagnetic means, additional meansresponsive to the opening of said cover for deenergizing the air flowproducing means, and further means responsive to the complete opening'ofsaid cover for effecting the operation of said releasable bag ejectingmeans.

9. In a vacuum cleaner, the combination comprising a casing having anopening, a movable cover for opening-releasable means for hold- .furthermeans responsive to the completc'open- 10 ingyof. said cover, foreffectingthe. release of =said restraining means.

10. Inavacuumcleaner, the combination comprising a casing having anopening, amovable cover for saidopening, releasable means .forholdingsaid cover in closed position, means-for producing a How of air throughsaid casing, .a ,dust bag in said casing in the path of saidiairiflowfor separating entrained dirt irom,-said, air, releasablemeans forejecting said dust bag, mechanically operable triggering, means operablefor placing the ejecting means in condition .for operation,pneumatically operable diaphragmv means for operating said triggeringmeans andsaid cover releasing means, valve :means .for controlling saidpneumatically operable means, electromagnetic means for actuating saidvalve means, .difierential air pressure responsive means operative uponthe attainment of a'predetermined pressure difference between theinsideandoutsideof the ,dust bag for energizing said electromagnetic,vmeans, means responsive to opening of said. cover for releasing themeansior ejecting said dustflbag, Whenever said ejecting means hasbeenwplaced in condition for operation, a cut-out means for renderingsaid electromagnetic means inoperative, and means on the dust bagforactua'ting said cut-out means to render the automatic ejecting meansinoperable.

11. In a vacuum cleanerfla casing having,. an opening, a movable 'coverfor said opening, means for producing flow of-air through saidcasinandust separating bag in saidicasing .inthepaithof air now therethrough,spring biased meansjior ejecting said bag from said casingthroughsaidopening, first latching meansfor retaining said ejecting means in fully.retractedposition, means responsive to a predetermined pressure .Idropthrough said bag for releasing said first latching means and for openingsaid cover, secondlatching means for-arresting movement of saidejecting' means after the, latter has been. releasedby said firstlatching means, and meansresponsive to opening of said cover forvreleasing said second latching means.

12. In a vacuum cleaner, a casing having-an opening, a movable coverforsaid opening, electrically driven means for producing fiow ofuairthrough said casing, means for supplying current to said electricallydriven. means; a dustseparating bag in said casing in .the pathof airflow therethrough, spring biased means .for ejecting said bag fromsaidcasing through saidopening, first latching means for retaining saidejecting means in fully retracted position, means responsive to apredetermined pressure .drop through said bag for-opening said cover-andfor releasing said first latching means, second latching means forarresting movement of said ejecting-:means after the latter has .beenreleased by saidifirst latching means, and means responsiveto opening ofsaid'cover for interrupting said'supply of current and for releasingsaidtsecondailatching means.

13. In a vacuum cleaner,acasingAhaVingEan opening, a movable cover forsaidopeninggmeans for producing flow of air through said. casing,,-adust separating member in said casing in theipath of .air' flowtherethrough, pneumaticmeans for opening said cover, valve meansfor-controllin said pneumatic means, electromagnetic means for actuatingsaid valve means, andnmeans'responsive to difference in pressureatoppositesides ofv said dust-separating member for operating saidelectromagnetic means.

14. In a vacuum cleaner, a casing having an opening, means for producingflow of air through said casing, a dust separating container in saidcasing in the path of air flow therethrough, spring biased means forejecting said container from said casing through said opening,pneumatically operated means for releasing said ejecting means,

valve means for controlling said pneumatically operated means,electromagnetic means for actuating said valve means, and meansresponsive to difference in pressure at opposite sides of said dustseparating container for operating said electromagnetic means.

15. In a vacuum cleaner, a casing having an opening, a movable cover forsaid opening, means for producing flow of air through said casing, adust separating container in said casing in the path of air flowtherethrough, spring biased means for ejecting said container throughsaid opening, pneumatically operated means for opening said cover andreleasing said ejecting means, valve means for controlling saidpneumatically operated means, electromagnetic means for actuating saidvalve means, and difierential pressure responsive means subjected to thepressures at opposite sides of said dust separating container foroperating said electromagnetic means.

16. In a vacuum cleaner, a casing having an opening, a movable cover forsaid opening, fan means for creating a pressure in said casing differentfrom atmospheric pressure to thereby produce flow of air through thecasing, a dust separating member in said casing in the path of air flowtherethrough, pneumatically operable means for opening said cover, valvemeans for controlling the application to said pneumatic means of thepressure difierence created by said fan, electromagnetic means foractuating said valve means, and means responsive to difference inpressure at opposite sides of said dust separating member due to thepressure drop of the air flowing therethrough for operating saidelectroma netic means.

17. In a vacuum cleaner, a casing having an opening, a movable cover forsaid opening, fan means for creating suction in said casing to therebyproduce flow of air therethrough, a dust separating member in saidcasing in the path of air flow therethrough, a power diaphragm foropening said cover, valve means for controlling the application of saidsuction to said diaphragm, electromagnetic means for actuating saidvalve means, an electric switch for energizing said electromagneticmeans, and a control diaphragm responsive to difference in pressure atopposite sides of said dust separating member due to the pres sure dropof air flowing therethrough for operating said switch.

18. In a vacuum clearer, a casing having an opening, a movable cover forsaid opening, means for producing flow of air through said casing, adust separating bag in said casing in the path of air flow therethrough,spring biased means for ejecting said bag from said casing through saidopening, first latching means for retaining said ejecting'means in fullyretracted position, pneumatic means for opening said cover and forreleasing said first latching means, valve means for controlling saidpneumatic means, electromagnetic means for actuating said valve means,means responsive to difierence in pressure at opposite sides of saiddust bag for operating said electromagnetic means, second latching meansfor arresting movement of said ejecting means after the latter has beenreleased by said. first latching means, and means responsive to openingof said cover for releasing said second latching means. I 19. In avacuum cleaner, a casing having a opening, a movable cover for saidopening, electricall driven means for producing flow of air through saidcasing, means for supplying current to said electrically driven means, adust separating bag in said casing in the path of air flow therethrough,spring biased means for ejecting said bag from said casing through saidopening, first latching means for retaining said ejecting means in fullyretracted position, pneumatic means for opening said cover and forreleasing said first latching means, valve means for controlling saidpneumatic means, electromagnetic means for actuating said valve means,means responsive to difierence in pressure at opposite sides of saiddust bag for operating said electromagnetic means, second latching meansfor arresting 1 movement of said ejecting means after the latter hasbeen released by said first latching means, means responsive to partialopening of said cover for interrupting said supply of current, and meansresponsive to substantially complete opening of said cover for releasingsaid second latching means.

20. In a vacuum cleaner, a casing having an opening, means for producingflow of air through said casing, a dust separating container in saidcasing in the path of air flow therethrough, spring biased means forejecting said container from said casing through said opening, meansresponsive to an increase in pressure drop through said container forreleasing said ejecting means, and means associated with said dustseparating container for rendering the pressure responsive meansinoperative.

21. In a vacuum cleaner, a casing enclosing a dust receptaclecompartment with an opening to the exterior, a dust separating memberinsertable into said compartment through said opening, means forproducing a flow of air through said member, a movable cover for saidopening, pneumatically operated means for controlling the opening ofsaid cover, valve means for controlling said pneumatic means, and meansresponsive to difference in pressure at opposite sides of said dustseparating member for controlling said valve means.

22. In a vacuum cleaner, a casing enclosing a dust receptaclecompartment with an opening to the exterior, means for producing aflow'of air through said compartment, a dust receptacle in saidcompartment in the path of air flow, spring biased means for outwardlymoving said dust receptacle, pneumatically operated means for'releasingsaid spring biased means, valve means for controlling said pneumaticmeans, and means responsive to difference of pressure at opposite sidesof said dust receptacle for operating said valve means.

GUSTAF EINAR LOFGREN. ROBERT C. LAMPE. JOHN '1". FERRARIS.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,192,224 Forsberg Mar. 5, 1940 2,320,368 Leather June 1, 19432,325,188 Lofgren July 27, 1943 2,498,102 White Feb. 21, 1 950 2,580,644Lofgren Jan. 1, 1952

